HTML Encoding Explained — Developer Guide
Learn why HTML encoding matters, which characters to escape, and when encoding prevents XSS — with a link to the free browser encoder.
Encode HTML online free →
HTML encoding converts special characters into HTML entities so they display as text instead of being interpreted as markup. This prevents broken layouts and is essential for XSS (cross-site scripting) prevention when rendering user-generated content.
Characters that must be encoded
- < becomes < (prevents opening tags)
- > becomes > (prevents closing tags)
- & becomes & (prevents entity injection)
- " becomes " (safe inside attributes)
- ' becomes ' (safe inside single-quoted attributes)
When to encode HTML
- Displaying user-generated content on web pages
- Inserting dynamic values into HTML templates
- Embedding JSON or code snippets in HTML
- Building email templates with dynamic data
How to encode HTML online
- Paste plain text into the Encode tab — entities appear instantly
- Switch to Decode to reverse entities back to characters
- Use for quick XSS checks before deploying template changes
- Processing stays in your browser — safe for proprietary copy